Closure structure for paper bags

ABSTRACT

A paper bag having a bottom wall, an open upper end, a front and rear wall in opposed relation connnected by side walls foldable to collapsed positions between said front and rear walls and expandable to positions at right angles to said front and rear walls. The upper marginal portion of the rear wall is co-planar therewith, and the corresponding upper marginal portion of the front wall is folded to overlie the outer surfaces of the front wall. When the upper end of the bag is collapsed over articles in the bag, the inner surface of said marginal portion on said rear wall and the outwardly exposed surface on said marginal portion on the front wall will be parallel, one above the other and contiguous therewith, and the upper end portions of said side walls will be infolded to lie between said front and side walls, as the upper free edges of said side walls terminate at said marginal portions. A coating of a conventional non-tacky, pressure sensitive adhesive, such as latex gum is inseparably bonded to said inner and exposed surfaces on said marginal portions, which adhesive coatings are adherent to each other so that by unfolding the folded marginal portion to a position coplanar with the front wall and pressing it against the marginal portion of the rear wall the bag will be tightly sealed against ingress or egress of gaseous or liquid fluids into or out of the bag at the open end.

United States Patent Chrysanthis et al.

[ 51. June 13, 1972 [54] CLOSURE STRUCTURE FOR PAPER BAGS [72] Inventors: Chris A. Chrysanthis, Daly City; George Chris Kourioglou, San Francisco, both of Calif.

[731 Assignees: Alex A; Chrysanthis, Dale City, Calif;

Tony Haldezos, part interest to each [22] Filed: Nov. 12,1970

[21] Appl. No.1 88,800

Primary Examiner-Donald F. Norton Attorney-Boyken, Mohler, Foster & Schwab [5 7] ABSTRACT A paper bag having a bottom wall, an open upper end, a front and rear wall in opposed relation eonnnected by side walls foldable to collapsed positions between said front and rear walls and expandable to positions at right angles to said front and rear walls.

The upper marginal portion of the rear wall is co-planar therewith, and the corresponding upper marginal portion of the front wall is folded to overlie the outer surfaces of the front wall. When the upper end of the bag is collapsed over ar ticles in the bag, the inner surface of said marginal portion on said rear wall and the outwardly exposed surface on said marginal portion on the front wall will be parallel, one above the other and contiguous therewith, and the upper end portions of said side walls will be infolded to lie between said front and side walls, as the upper free edges of said side walls terminate at said marginal portions.

A coating of a conventional non-tacky, pressure sensitive adhesive, such as latex gum is inseparably bonded to said inner and exposed surfaces on said marginal portions, which adhesive coatings are adherent to each other so that by unfolding the folded marginal portion to a position coplanar with the front wall and pressing it against the marginal portion of the rear wall the bag will be tightly sealed against ingress or egress of gaseous or liquid fluids into or out of the bag at the open end.

3 Claims, 6 Drawing Figures PATENTEDJUM 13 I972 INVENTORS R Y SA N T H l 5 CHRIS A. CH I SB EORGE C.KOURTOGL0U CLOSURE STRUCTURE FOR PAPER BAGS BACKGROUND OF INVENTION An expandable paper bag, of the conventional type having the bellow type side walls foldable inwardly to between the front and rear walls of the bag. While the bottom wall is foldable to a position over the front wall is old, such bags are readily packaged fiat for shipment, storage, or for use in dispensing cabinets. When expanded, such bags have a large capacity as compared to flat envelopes having only two sides and a closure flap, but heretofore either the open ends have been closed by folding the front and rear walls on themselves, with the infolded side walls disposed between them at their open ends, and then held closed by the hand or relatively complicated sealing means has been provided leaving openings for leakage of the odors from the contents of the bag or for the gaseous or liquids associated with the contents. In many instances the manipulations required to effect closure are of a character in which constant contamination of the hands by the contents is imminent, which may be dangerous as well as unpleasant, as where the bags are used in hospital operating rooms for surgical dressings, or for disposal of waste and garbage in homes or elsewhere.

In bags that have required overfolding of the upper ends of the bags to effect closure thereof there is a loss in the capacity of the bag, as well as an increase in bulk at the open end after closure.

SUMMARY One of the objects of the invention is the provision of disposable bags of generally conventional structure that may be made by conventional machines without increase in materia1, and which bags are so constructed that they may be closed after filling, by a single, simple operation by the fingers of one hand of a person, and when so closed, will be sealed against escape of odors, noxious or otherwise, as well as retaining the solids that have been placed in the bags.

Another object of the invention is the provision of a disposable bag having a front and rear wall connected by side walls of the bellows-type adapted to fold inwardly between the front and rear wall at the open end of the bag, and which front and rear wall have opposed upper marginal portions having a non-tacky pressure sensitive adhesive on their opposedly facing sides that will adherently secure the upper marginal portions of said front and rear walls together above said side walls when the latter are in-folded to positions between said front and rear walls at their upper ends. Said marginal portions will hold said front and rear walls together when in said adherent engagement and will seal the bag closed against ingress and egress of fluid as well as retaining the solids within the bag.

Other objects and advantages will appear in the description and drawings.

DESCRIPTION OF DRAWINGS FIG. 1 is an elevational view of a flattened, collapsed bag showing the upper marginal portions as seen from the adhesive carrying side.

FIG. 2 is a side-elevational view of the bag of FIG. 1 opened.

FIG. 3 is a side-elevational view similar to FIG. 2, showing the filled bag closed.

FIG. 4 is a fragmentary, greatly enlarged elevational view of the upper portion of the bag shown in FIG. 3.

FIG. 5 is a greatly enlarged view illustrating the closing of the bag in a single operation.

FIG. 6 is an isometric view showing a pad of separately removable bags of slightly modified structure.

The flat folded bag of FIG. 1 is a conventionally made paper bag except for the structure at the upper open end. Said bag has front and rear planar walls 1, 2 (FIG. 2) and a bottom wall 3 that is normally folded against the front side of the bag in the usual way when the bag is flattened for storage and shipment or before use.

Side walls 4, 5 are of the bellows type, connecting the front and rear walls. Each wall 4, 5 is folded on itself along fold lines 6 when the bag is flattened as seen in FIG. 1 but is readily expanded to the position shown in FIG. 2 when the bag is opened for filling. The foregoing structure is common in paper bags.

The front and rear walls 1, 2 have upper, horizontally extending marginal portions 7, 8 that are of equal width, that extend equally beyond the terminal upper edges 9 (FIG. 2) of the side walls 4, 5. The marginal portion 7 is planar with the rear wall, while the marginal portion 8 is folded against or over the outwardly facing side of the front wall 1 (FIG. 2). The terminal end edges 10 of said marginal portions extend to the upper terminal edges 9 of the side walls 4, 5.

The marginal portion 8 on front wall 1 is folded along a fold line 11 (FIG. 2) that extends across the front wall 1 between points at the upper forward ends of the terminal upper edges 9 of side walls 4, 5. Said marginal portion is so folded from broken line position 12 (FIG. 2) in which it is planar with the front wall 1, and in this position it is seen that the inner surfaces of marginal portions 7, 8 are in opposedly facing relatron.

When the bag is folded to flat position as seen in FIG. 1, and sides 1, 2 are substantially together with the side walls 4, 5 folded between them, and marginal portion 8 is folded to overlie the outer side of front wall 1, it is seen that the inner surface of marginal portion 8 (before folding) face outwardly of the front wall 1 and are contiguous along fold line 11. When unfolded along fold line 11 and restored to position 12, the said inner surfaces of the marginal portions will again face each other.

The above described inner surfaces are coated with conventional latex gum 13 (FIG. 1) of the type commonly used on envelopes, which coating is inseparably adhered to the respective marginal portions. The exposed surfaces of the adhesive will tightly adhere to each other but not to uncoated material, and is substantially non-drying. These are normal and well known characteristics of the adhesive, which will be designated a non-tackypressure sensitive adhesive to distinguish from the tacky pressure sensitive adhesive such as com monly used on SCOTCPF tape and which will adhere to similarly coated and uncoated material alike.

A bag of the foregoing structure may be as freely handled as any conventional paper bag as long as the adhesive coated surfaces are not brought into contact with each other. Thus the bags may be stacked or held in a suitable magazine for separate withdrawal, without adhering to each other.

FIG. 6 shows a modification in which an extension, or stub, 16, planar with each marginal portion 7 and connected thereto along a perforated line, or tear line 17 may be secured together by staples 18, or any other suitable means, to form a pad of bags. Such pad may be secured along said stubs 16 to a panel 19 from which the outermost bag :may be separately torn from its stub. The bags of the pad below tear lines 17 will not adhere to each other, and each bag so removed from its stub will correspond to the bags of FIGS. 1 3.

In operation, after opening a bag and filling,it, the front and rear walls 1, 2 may be brought together between the thumb and forefinger of one hand 20 (FIG. 5) of a person for holding the filled bag while in one motion the thumb and forefinger of the other hand 21 may elevate the marginal portion 8 and pinch marginal portions 7, 8 between said fingers while sliding the thumb and forefinger of hand 21 in the direction of the arrow 22 from one of the ends of the marginal portions 7, 8 to the other.

The side walls 4, 5 will be in'folded to lie between the front and rear walls at the marginal portions 7, 8 when the above operation is performed, thus the marginal portions will not only secure the upper end of the bag closed but will hold the upper ends of side walls 4, 5 folded between the front and rear walls at the upper end of the bag (FIGS. 3, 4).

As seen in FIG. 4, the bag, when thus closed, will be tightly sealed, inasmuch as the only places where slight leakage of air or fluid within the bag could theoretically occur would be at points 23. The walls of the bag as seen in FIG. 4 are greatly exaggerated for clarity of explanation. Actually they are usually no thicker than one of the outline lines, hence the bag would be virtually hermetically sealed when filled and closed as described, and if the paper is processed to be resistant to passage of moisture therethrough, the bag would also be moisture proof.

The bags may, of course, be of any desired size and the actual structure that is important is at the open end of the bag. While the bag is referred to as a paper bag, it may be of any suitable sheet material having sufficient stiffness to maintain the marginal portion 8 substantially in the position shown in FIG. 2 until initially elevated as seen in FIG. 5 to thereby eliminate accidental unfolding and adherence of the marginal portions together.

It is also to be understood that the use of the words front," rear" and side" for designating the lateral walls of the bag are primarily for the purpose of distinguishing between the walls. In certain instances the bags may be disposed horizontally for side loading, in which case the front wall may be the upper wall, and the rear wall the lower one, and the mouth or open end of the bag may be closed and sealed by merely pressing the unfolded marginal portion 8 against marginal portion 7 while the latter was on the surface supporting the bag.

WE CLAIM:

1. In a collapsible bag of sheet material having planar front and rear walls, a bottom wall and an upper open end, and collapsible side walls connecting said front and rear walls and connected with said bottom wall for out-folding from collapsed positions between said front and rear walls in which said front and rear walls are substantially in face-to-face engagement to expanded positions generally normal to said front and rear walls spacing the front and rear walls apart to open said upper end for filling the bag, the improvement comprismg:

a. said side walls being of corresponding width and corresponding height having terminal upper edges at the open end of the bag extending between said front and rear walls,

b. parallel upper marginal portions on said front and rear wall in which the marginal portion on said rear wall is coplanar with the latter and extends upwardly above said terminal upper edges of said side walls and having an inner surface on the side adjacent said front wall,

a fold on said front wall extending across the latter between the terminal ends of said side walls at said front wall and the upper marginal portion of said front wall being folded along said fold line to overlie said front wall below said fold line providing an exposed outer surface facing in the same direction as said inner surface on the upper marginal portion of said rear wall,

. a non-tacky, pressure-sensitive adhesive coating bonded to and covering said inner and exposed surfaces of said marginal portions having an adherent affinity for adhesive of the same type for tightly securing said marginal portions together when said adhesive covered surfaces are pressed together,

. said inner surface and said outer exposed surface being contiguous along said fold line when said bag is collapsed, and when an object or objects are within said bag and the upper portions of said front and rear walls adjoining said marginal portions are brought together with the upper portions of said side walls infolded to lie between said front and rear walls adjacent said marginal portions, whereby said marginal portions will be adherently secured together from said terminal upper edges of said side walls upwardly upon unfolding the upper marginal portion of said front wall and pressing its adhesive covered side against the adhesive covered side of the upper marginal portion of said rear wall.

. In a collapsible bag as defined in Claim 1' said marginal portions being of equal width and length and having terminal end edges in upward extension of the side edges of said front and rear walls and the upper terminal edges of said side walls being at the adhesive coating on said marginal portions.

A bag as defined in claim 1;

f. an upward extension integral and coplanar with the upper marginal portion on said rear wall, weakened along a line defining the juncture between said extension and said marginal portion,

. a plurality of said bags in collapsed condition depending from said extensions supporting said bags with the adhesive covered sides of said marginal portions facing in the same direction, and means supporting said extensions for successively removing said bags therefrom along the line of weakness connecting each bag with its extension.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 9 254 Dated June 13, 1972 Inv t )Chris A. Chrysanthis and George Chris Kourtoglou It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the title page, in Item [72] "Kourioglou" should read -Kourtoglou--; in Item [73] T'Dale" should read -D aly; and in Item [73] after "Haldezos", should be inserted --San Francisco, Calif.--.

Signed and sealed this 9th day of January 1973..

(SEAL) AtCCST! EDWARD M.I"I.,ETCHER,JR.

ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM O-1050 (10-69) USCOMM-DC 60376-P69 u a GOVERNMENT PRINTING OFFICE: may 0--366314 

1. In a collapsible bag of sheet material having planar front and rear walls, a bottom wall and an upper open end, and collapsible side walls connecting said front and rear walls and connected with said bottom wall for out-folding from collapsed positions between said front and rear walls in which said front and rear walls are substantially in face-to-face engagement to expanded positions generally normal to said front and rear walls spacing the front and rear walls apart to open said upper end for filling the Bag, the improvement comprising: a. said side walls being of corresponding width and corresponding height having terminal upper edges at the open end of the bag extending between said front and rear walls, b. parallel upper marginal portions on said front and rear wall in which the marginal portion on said rear wall is coplanar with the latter and extends upwardly above said terminal upper edges of said side walls and having an inner surface on the side adjacent said front wall, c. a fold on said front wall extending across the latter between the terminal ends of said side walls at said front wall and the upper marginal portion of said front wall being folded along said fold line to overlie said front wall below said fold line providing an exposed outer surface facing in the same direction as said inner surface on the upper marginal portion of said rear wall, d. a non-tacky, pressure-sensitive adhesive coating bonded to and covering said inner and exposed surfaces of said marginal portions having an adherent affinity for adhesive of the same type for tightly securing said marginal portions together when said adhesive covered surfaces are pressed together, e. said inner surface and said outer exposed surface being contiguous along said fold line when said bag is collapsed, and when an object or objects are within said bag and the upper portions of said front and rear walls adjoining said marginal portions are brought together with the upper portions of said side walls infolded to lie between said front and rear walls adjacent said marginal portions, whereby said marginal portions will be adherently secured together from said terminal upper edges of said side walls upwardly upon unfolding the upper marginal portion of said front wall and pressing its adhesive covered side against the adhesive covered side of the upper marginal portion of said rear wall.
 2. In a collapsible bag as defined in Claim 1; f. said marginal portions being of equal width and length and having terminal end edges in upward extension of the side edges of said front and rear walls and the upper terminal edges of said side walls being at the adhesive coating on said marginal portions.
 3. A bag as defined in claim 1; f. an upward extension integral and coplanar with the upper marginal portion on said rear wall, weakened along a line defining the juncture between said extension and said marginal portion, g. a plurality of said bags in collapsed condition depending from said extensions supporting said bags with the adhesive covered sides of said marginal portions facing in the same direction, and h. means supporting said extensions for successively removing said bags therefrom along the line of weakness connecting each bag with its extension. 